Only 20 percent of announcements made at subway stations were understandable and correct during the first half of this year, according to the twice-annual report card NYC Transit releases today.

Required announcements on buses were made only 58 percent of the time.

This would not surprise most subway riders who’ve given up attempts to decipher the noise that spews form the public address systems at many stations.

According to the Passenger Environment Survey, 28 percent of announcements were completely unintelligible, 36 percent were “marginally understandable,” and 16 percent were “partially understandable.” These figures are virtually unchanged since last year and in some categories slightly worse.

Transit officials say the public address systems are being upgraded, but admit that the equipment at many locations is far from ideal. Overall, subway cars seem to fare better than stations, says the survey. Every subway car contains the most up-to-date subway map, but less than half of all stations contain “legible/correct” maps.